腐烂茎线虫rDNA-ITS序列分析

Sequence Analysis of Internal Transcribed Spacer of Ditylenchus destructor Ribosomal DNA

利用一对通用引物rDNA1/rDNA2扩增6个腐烂茎线虫供试群体的rDNA-ITS区域,获得序列长度不等的片段。Des-1、Des-2和Des-3群体扩增片断长度均为1130bp。而Des-5、Des-6和Des-7群体的扩增片段长度均为942bp,与以上群体相比,在ITS区具有一个188bp的缺失片段。序列比对后确定缺失片段位于ITS1区,而且该片段含有多个可重复小片段,这可能是造成碱基缺失的原因。根据遗传进化分析可将供试线虫分为两个大的群体。

The internal transcribed spacer（ITS） of rDNA from 6 nematode（Ditylenchus destructor） populations in 3 host plants were amplified and sequenced. The amplification of the rDNA-ITS region from Des-1, Des-2 and Des-3 populations produced one single fragment of 1 130 bp, whereas the PCR products of the ITS from Des-5, Des-6 and Des-7 populations were 942 bp. The ITS section was proved by the sequence of rDNA-ITS region from the GenBank. There was an absent fragment of 188 bp in the ITS1 section of Des-5, Des-6 and Des-7 populations. In the absent section were found some small repeated fragments which might be the main reason for the absence in the fragment. The 6 nematodes can be grouped into two large populations based on the analysis of their genetic evolution.